Answer: The electron transport chain.
Step-by-step explanation:
Cellular respiration is defined as the mechanism by which living organisms converts organic substances from food such as glucose with the use of oxygen into energy-carrying biomolecules (e.g. adenosine triphosphate or ATP). There are different stages of cellular respiration which includes:
--> glycolysis,
--> pyruvate oxidation,
--> the citric acid or Krebs cycle, and
--> oxidative phosphorylation.
The oxidative phosphorylation also referred to as the ELECTRON TRANSPORT CHAIN occurs in the inner membrane of the mitochondria. It transfers electrons donated by the reduced electron carriers NADH and FADH2 (obtained from glycolysis, the citric acid cycle or fatty acid oxidation) through a series of electrons acceptors, to oxygen.
The electron transport chain is said to produces most of the energy which is 34 ATP molecules, as compared to only 2 ATP for glycolysis and 2 ATP for Krebs cycle.